Remove no longer needed gitdate tag

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/html/git-commit-info.html

-{% load i18n %}{% load translations %}
+{% load i18n %}
 <span class="git-commit ui-corner-all tooltip">{{ commit.hexsha|slice:":8" }}<span class="tooltip-content">
 {% blocktrans with commit.hexsha as hash %}Commit {{ hash }}{% endblocktrans %}<br />
-{% blocktrans with commit.author.name as author and commit.authored_date|gitdate as date %}Authored by {{ author }} on {{ date }}{% endblocktrans %}
+{% blocktrans with commit.author.name as author and commit.authored_date|date:"DATETIME_FORMAT" as date %}Authored by {{ author }} on {{ date }}{% endblocktrans %}
 </span></span>

weblate/trans/templatetags/translations.py

@@ -282,17 +282,6 @@ def show_checks(checks, user):
     }
 
 
-@register.filter
-def gitdate(value):
-    '''
-    Formats timestamp as returned byt GitPython.
-    '''
-    return date_format(
-        datetime.fromtimestamp(value),
-        'DATETIME_FORMAT'
-    )
-
-
 def naturaltime_past(value, now):
     """
     Handling of past dates for naturaltime.